/*********************************************************************
 * Copyright (C) 2002 Andrew Khan
 * <p>
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2.1 of the License, or (at your option) any later version.
 * <p>
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Lesser General Public License for more details.
 * <p>
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
 ***************************************************************************/

package jxl.write.biff;

import jxl.biff.IntegerHelper;
import jxl.biff.Type;
import jxl.biff.WritableRecordData;

import java.util.ArrayList;
import java.util.Iterator;

/**
 * Indexes the first row record of the block and each individual cell.  
 * This is invoked by the sheets write process
 */
class DBCellRecord extends WritableRecordData {
    /**
     * The file position of the first Row record in this block
     */
    private int rowPos;

    /**
     * The position of the start of the next cell after the first row.  This
     * is used as the offset for the cell positions
     */
    private int cellOffset;

    /**
     * The list of all cell positions in this block
     */
    private ArrayList cellRowPositions;

    /**
     * The position of this record in the file.  Vital for calculating offsets
     */
    private int position;

    /**
     * Constructor
     *
     * @param rp the position of this row
     */
    public DBCellRecord(int rp) {
        super(Type.DBCELL);
        rowPos = rp;
        cellRowPositions = new ArrayList(10);
    }

    /**
     * Sets the offset of this cell record within the sheet stream
     *
     * @param pos the offset
     */
    void setCellOffset(int pos) {
        cellOffset = pos;
    }

    /**
     * Adds a cell
     *
     * @param pos
     */
    void addCellRowPosition(int pos) {
        cellRowPositions.add(new Integer(pos));
    }

    /**
     * Sets the position of this cell within the sheet stream
     *
     * @param pos the position
     */
    void setPosition(int pos) {
        position = pos;
    }

    /**
     * Gets the binary data for this cell record
     *
     * @return the binary data
     */
    protected byte[] getData() {
        byte[] data = new byte[4 + 2 * cellRowPositions.size()];

        // Set the offset to the first row
        IntegerHelper.getFourBytes(position - rowPos, data, 0);

        // Now add in all the cell offsets
        int pos = 4;
        int lastCellPos = cellOffset;
        Iterator i = cellRowPositions.iterator();
        while (i.hasNext()) {
            int cellPos = ((Integer) i.next()).intValue();
            IntegerHelper.getTwoBytes(cellPos - lastCellPos, data, pos);
            lastCellPos = cellPos;
            pos += 2;
        }

        return data;
    }
}
